This application is directed to wireless communications and, more particularly, to shared tertiary chain between GPS and 1× to improve LTE throughput on primary and secondary chains in wireless communications.
Electronic devices such as portable computers and cellular telephones are often provided with wireless communication capabilities. For example, electronic devices may use long-range wireless communication circuitry such as cellular telephone circuitry and WiMAX (IEEE 802.16) circuitry. Electronic devices may also use short-range wireless communication circuitry such as WiFi® (IEEE 802.11) circuitry and Bluetooth® circuitry.
In some devices, it may be desirable to support multiple radio access technologies. For example, it may be desirable to support newer radio-access technologies for handling data sessions and older radio-access technologies for supporting voice calls. Examples of different radio-access technologies that have been used in cellular telephones include Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Code Division Multiple Access (CDMA) (e.g., CDMA2000 including standards such as CDMA2000 1×RTT or 1×), and Long Term Evolution (LTE).
In certain single radio LTE implementation, LTE and 1× operate in a hybrid mode of operation. This means that while LTE is operating using the single radio (i.e., in data traffic mode), the LTE operation can get interrupted periodically by 1× tune-aways. In this way, the single radio can periodically tune-away from an active LTE connection to check for paging messages, etc. on the 1× system, as well as, e.g., to measure the RF conditions.
A tune-away, for example, can last approximately 100-200 msec, depending on network equipment design and 1× network performance, but mobile devices can stay on 1× for a much longer time. The following items describe example scenarios that may result in long tune-away times: 1) Voice calls—when the subscriber gets paged and picks up a voice call on the 1× interface, which might list a long time, 2) Idle handoffs—tune-away can last around a second, 3) Registrations—tune-away can last from a second or two to more than 10 seconds if the mobile device finds out that it has to register after tuning-away to 1×, 4) System lost—Tune-aways can last more than 5 seconds, up to tens of seconds. These system lost tune-away could be caused by common RF problems, like coverage holes, pilot pollution, or rapidly changing pilots. These 1× tune-away events can negatively impact LTE throughput.
Therefore, it would be desirable to provide improved ways to support multiple radio access technologies in a single-radio electronic device without reducing LTE throughput.